


Experiment

by Tacobellrey



Category: Durarara!!
Genre: Consensual Underage Sex, Crushes, First Kiss, Hand Jobs, High School, M/M, Manipulation, Possessive Behavior, Sexual Tension
Language: English
Status: Completed
Published: 2020-08-25
Updated: 2020-08-25
Packaged: 2021-03-07 01:01:21
Rating: Explicit
Warnings: Underage
Chapters: 2
Words: 3,221
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/26108365
Author URL: https://archiveofourown.org/users/Tacobellrey/pseuds/Tacobellrey
Summary: Shinra ask Izaya if he'd be a willing participant in some sexual experimentation.
Relationships: Kishitani Shinra & Orihara Izaya
Kudos: 15





	1. Offer

**Author's Note:**

> Hey so, newbie here! This is the first story I've officially decided to post even though it's been sitting for a while in my files. My goal was to keep it short and sweet. I'd appreciate any comments or reviews. Especially constructive criticism.

“Really? An experiment?” Izaya asks his only friend in the high school cafeteria, who just so casually asked if he’d be willing to help him out with a new ‘project’ He keeps a half-hearted smirk, careful no to clue Shinra into the fact that such an experiment was exactly the type of thing he’d planted in Shinra’s head with some carefully chosen words and body language. The nerd keeps an eager smile and nods before continuing. 

“Yeah, I mean, if you’d be interested and aren’t too busy getting into trouble or trying to get yourself killed.” Shinra says almost proudly. It’s just them at the long table in the otherwise crowded room. Shinra approached Izaya all on his own, currently the only one brave enough to sit with the delinquent. Izaya snorts. 

“Well that depends, how much time will you need to cut me open and have your fun with some of my organs?” He snarks softly. This gets a cute laugh from Shinra. Izaya keeps his cool gaze on his friends' easily amused face. 

“No! No! Not cutting open! This is….uh…..this is a more behavioral study.” He states simply. This gets a raised brow from Izaya, thinking, 

You’re doing well Shinra. Right on track. 

“Behavioral? Well, I was unaware you were interested in anything unrelated to the bare bones of biology.” Izaya then turns to take a bite from his bento box. Shinra leans forward on his elbows and watches him eat. 

“Yeah well, this isn’t for school. It’s just a curiosity I’ve had, and I suspect one you’ve had too.” He clarifies. Izaya puts on a surprised expression and watches Shinra grin with glee. 

It is. But please tell me. 

“Well now I must know, what curiosity have we had?” He asks, putting down his chopsticks and pushing away the half eaten container. Shinra sits up straight and fixes his glasses before clearing his throat. 

“You’ve never kissed anyone right?” The nerdy friend asks the one dressed in red and black maybe a bit louder than necessary. Izaya opens his mouth, but halts the next few words. He shakes his head. 

“I-wait what?” 

“I mean I’m guessing you haven’t. I’ve never seen you with a girl or boyfriend, and you don’t even hug your own sisters. I’m guessing you’ve never practiced human affection so to speak.” Shinra somewhat accurately deduces. Izaya pretends to be slightly offended. He huffs and rolls his eyes. 

“That doesn’t mean anything.” Shinra scoots closer, making Izaya’s heart skip a beat in mild arousal. 

Come closer. 

“So have you?” 

“Have I what?” 

“Ever kissed anyone then? I mean you can tell me if you have. I’ll keep it a secret.” He says with a wink. 

Oh I’m gonna tear you up you beautiful nerd. 

Izaya looks down, baiting Shinra with some slight shame. “Not yet.” He says in a low tone. This gets the welcome feeling of Shinra planting his hand on Izaya’s shoulder and squeezing. He gets a bit touchy without realizing it. Not that Izaya was complaining. 

“Well that's perfect, cause I haven’t either. I’ve just been thinking, we’re both about to be seniors next year who’ve never done such a basic thing as kissing. It might be embarrassing not to know how once we start dating.” He tells Izaya, who’s already well aware of this mild insecurity Shinra’s had. It was easy to exploit. Izaya pretended to think. 

“Well so what? Is kissing supposed to be hard?” 

“Well no, but from what I understand it does take some practice.” 

“I see. So you want to use me to practice your perverted fantasies.” Said to anyone else Izaya might get punched in the face or watch someone run off crying. Shinra just laughs. 

“Only as perverted as necessary.” He tells him simply. That’s the beautiful thing about Shinra, he was just so simple. He saw no need to lie or fake his way through life, even if it only earned him one friend, who had a very fun time playing around with his beloved humans. What could Izaya say? He was ready to play with him. Izaya reaches for Shinra’s hand and moves it off. Not cause he wants to, but because he needs to play hard to get, just a little. 

“You flatter me.” 

“Is that a yes or a no?” 

“It’s an interesting offer.” 

“Come on, you’re not curious about that? I mean romance and sexuallity are part of being human.” 

“Not as much as the darker side of humanity. I find the hidden side of people far more interesting.” 

“Well people usually do this kind of stuff in private.” Shinra adds. Izaya snorts. He loves how hard Shinra’s trying, it’s time to get him to try harder. 

“And you think its a wise idea to willingly give me such information? Such private information, as you say.” He challenges. Shinra fixes his glasses and then lifts a finger. 

Ah, keep up with the cute shit and I might just have to lock you in my basement.

“Why not? I’d have the exact same thing on you. While you're the expert at blackmail and all, I don’t think it’s possible to blackmail someone who has something just as devastating on you.” He states back confidently. 

“Well, you’ve thought this though I see.” Shinra nods, then leans in closer. Izaya leans back though he savors the slight scent of his soon to be lover. 

“Any other questions?” He asks. 

“Only about a million.” 

“Too bad, lunch break is almost over, and I need an answer in the next 60 seconds.'' Shinra states then points to his watch. 

“Ah I see, think I’ll cave to the pressure.” Izaya notes. 

“Maybe.” Shinra says slyly, then half blushes. Izaya could have reached over and kissed him hard right there. Made that nerd his. Well, officially. Shinra already was, though only Izaya knew that. When he ran into a girl with a crush on him, he found some clever ways to handle the situation. Let’s just say the girls are settling in new schools. Luckily, Shinra never found out about the crushes, or seemed all that interested in his female classmates anyway. 

Izaya glances down at his lunch, still half eaten, but how could he think about food at a time like this? When his new toy was begging to play with him. He picks up the half eaten food and rises to take it to the trash. Shinra watches, Izaya lets him frown slightly before he dumps the food and turns back to cross his arms and stroll back over. 

“Eh, I suppose I could humor you.” Izaya says, then watches Shinra’s eyes grow wide before realizing that Izaya said yes. He jumps up and nearly shouts. 

“SO YOU’LL DO IT!” Izaya glances around at the nearby tables who caught the reaction and watches curiously. Their peers leave them be for the most part. Izaya waits a moment before responding, with a finger on his lips. Shinra shrinks back, a bit embarrassed by just how overeager that was. 

“Yes, I’ll do it.” Izaya tells him. Walking past Shinra, who can’t hold back the giant goofy smile. Izaya doesn’t mind, he simply pats him on the shoulder as he passes. “We’ll make arrangements later.” He tells him then walks right on out the cafeteria, leaving Shinra flustered and happy.


	2. The Experiment

**Summary for the Chapter:**

> Part Two.

Izaya pushes open the door to find his friend sitting at his desk, working hard on some other project, unaware of Izaya’s entrance until the classmate grunts out loud. Now he looks up and fixes his frames. 

“Ah hey Izaya!” He beams then rises as Izaya leans against the door frame and scans the room. It’s dark except for the lamp Shinra was using to read by. Some old medical book his dad probably gave him. He’s met the man once, that was enough. Shinra rises and gestures for Izaya to come in. 

“Please have a seat on the bed if you will.” He states, cheerful, but oddly professional. Izaya snickers. 

“Practicing for when you have some underground practice?” He says as he walks in and makes sure the door is shut. No one was home, but still. Just in case. 

“Oh, sure. And I expect that you’ll be my best customer.” Shinra easily retorts watching Izaya walk over to the bed next to the long window, with closed blinds. “Just let me finish this one problem, I’ll be with you shortly.” 

“Of course, take your time.” Izaya tells Shinra who sits back down and dives back into whatever problem he was referring to. Normally Izaya would help, but he’s content to sit with crossed arms and watch his friend. It’s quiet save for the sound of his pen scratching the paper. Izaya keeps his gaze locked on his friend, who surprisingly shows no sign of apprehension about what he was about to try with his friend in about two minutes. Neither was Izaya, but that wasn’t unusual. This was all his plan, he only got nervous when things didn’t go as planned, and by now he had Shinra wrapped around his finger. Shinra keeps himself hunched over the book, calmly focused as he usually was when the two studied. 

Shinra smiles once the problem is finished, closes the book, then turns back to Izaya, who sits with his default smirk. It was the face Shinra was most familiar with, and Izaya needed him to relax. 

Come over, I don’t bite. 

“Right then.” Shinra fixes his glasses then gets up to move right in front of Izaya, and look down at his schoolmate. An interesting approach. Especially with a smile on the whole time, although there is a hint of naughty glee he loved seeing in that nerdy face. 

“Sorry for the wait.” He tells him unsure of how to proceed. 

“It’s alright, I expected you to stall a little.” He flat out tells him. As a rule, Izaya had to tell the truth on occasion. Otherwise the little lies start to sound less convincing. 

Shinra shrugs. “If you say so oh great one.” He replies sarcastically. “I’m gonna assume you’re ready?” Shinra asks clearly before taking off his thin frames to tuck in the pocket of his shirt. Izaya snorts then shrugs. 

“Whenever you are, let’s just get this over with.” He answers coyly. At this Shinra half chuckles, then moves his face into Izaya’s without even the slightest hesitation. He doesn’t go in yet, which is also an interesting move. Shinra lets his face linger barely an inch away from Izaya’s mouth. Testing his defenses. He likely thought if he really went for it he’d get sliced. Izaya remains still, as his friend hovers. The tips of their noses touch gently. For a moment, Shinra closes his eyes and seems to absorb the closeness. Izaya leans back slightly to test Shinra right back. The nerd moves closer, not about to let Izaya get away. Izaya snickers. 

Good boy. 

“Well this is unexpected.” Shinra says softly, opening his eyes to lock with Izaya’s. 

“What’s so unexpected?” 

“How nervous you are.” Shinra answers then steps a bit closer, closing the last few inches of space between his legs and Izaya’s knees which fall slightly open.

“Oh? Am I?” He teases back, knowing it’ll spur his friend on. Shinra chuckles at this, but then does surprise Izaya a little by reaching out to take hold of his friend's shoulders to keep him still.

“Well unless you're always this tense.” Shinra comments giving both his shoulders a gentle rub that forces Izaya to fight the urge to lean back and moan at his playful touch. 

“Perhaps I am? Why do you offer massages? Is there any end to your endless list of tale-” 

Before Izaya can finish the comment, Shinra makes his move. Wise to be quick enough that Izaya can only blink in shock at the sudden and very warm connection that marks the beginning of the “experiment.” 

This was it. He won,and without knowing it, Shinra lost to his best friend. Izaya’s heart beat hard against his chest at the thrill of the victory, second only to the delicious lips kept pressed hard against his exploring with a curiosity that confirmed that yes, Izaya was his friend’s first. They’re both quiet for the first few seconds. Izaya keeps his eyes slightly open, unwilling to lose sight of Shinra’s reactions. His goal wasn’t just to steal some affection from his schoolmate. Every little move told Izaya something. 

Shinra keeps hold of his friend's shoulders as he pulls back slightly, then reconnects with more confidence. Izaya snorts and can’t help but wonder just how clinically he would take this. Or, would he get lost in the heat of Izaya’s mouth. Shinra pulls back again, ignoring the small wet smack of the disconnect as he blinks open and then hums to himself. Izaya snorts, then raises a brow. “Well?” 

“Well what?” 

“Is that it? Did you get everything you need for your little project?” Izaya teases letting his eyelids fall to gaze gently at his slightly flushed friend. 

“Hmmm, I’m not sure. I think a second run is needed.” He states before taking hold of the back of Izaya’s head with his right hand. Izaya watches as the face crashes back into his to resume testing him out. This time with much more vigor. 

Izaya had expected Shinra to sit down next to him, at eye level before starting, not this almost blatant display of dominance. Izaya’s forced to lean up and take a quick inhale while Shinra takes his time sinking down onto his face, and deeper into his mouth. 

A few telling twitches from his crotch, inspire Izaya to work to match Shinra’s pace. The hand squeezes into his hair, making Izaya wince slightly. It’s actually a smart move cause this time when Shinra opens his mouth Izaya opens his much wider without hesitation. Here is where the real experiment begins. 

Shinra wins a sudden and rather loud moan from Izaya when his friend’s hot and long tongue finds and gently rolls against his. He knew he’d taste perfect the moment he’d set eyes on him as a target. But the confirmation is nearly overwhelming. His new erection throbs wildly hard as they take turns sucking each other in. Izaya leans back, inviting Shinra to come even closer. His body needs the weight of his friends now that they’re both rock hard and in rhythm. Shinra sinks down lower, then pushes Izaya down onto his back without breaking the kiss. Izaya lands and gazes up at the blurry face eating into him on pure instinct. Shinra climbs on and lets his body sink down onto his slender friend's frame to pin him down. Izaya doesn’t mind. He’s in heaven kissing up as his friend grinds his hips against his to investigate just how highly aroused they both are. 

Izaya’s arms wrap around Shinra’s long back as the kissing gets wetter, messier, and more aggressive. Shinra leads the dance panting hard through his nose. Izaya runs his hands up his friend's back, more than ready to find out just how far he’ll let him go. The smooth hot skin that greets him melts and shivers at Izaya’s graceful fingers sliding up over each muscle, then back down letting his nails make long marks on the way. Shinra only kisses harder and lets his own hand reach down to start yanking at Izaya’s belt. 

Oh? What’s this? Not exactly part of the deal now is it? 

Izaya’s at his lower back when Shinra finds and takes firm hold of his cock through his boxers to rub and tease the moist head. Izaya starts to protest, but instead inhales sharply at the unexpected touch. What starts out as a tease over his boxers soon becomes his friend sliding his hand into the hem to pull him right out. All the while Shinra never breaks from his friends mouth. 

Then he snickers. Izaya turns his head and breaks the kiss, curious as to what’s so funny all the sudden. 

“Something on your mind?” He asks as he’s squeezed by his friends fist. 

Harder, rub it harder! 

“I’m just surprised, I didn’t think your dick would be left handed too.” He says then chuckles right in Izaya’s face. He rolls his eyes and then reaches for Shinra’s pants with his left hand, amazed that the boy somehow managed to catch that from this angle. 

“Well let's see then,” He says while he’s getting slowly pumped. Shinra’s cock is a little thicker but the head greets him with a few telling twitches of love as he uses his thumb to rub it in small circles. 

“Anything unusual?” Shinra asks, leaning back down into Izaya’s face, more than ready to resume the experiment. 

“Not at the moment.” Izaya answers as he’s pushed into a nice and hard kiss with his hand now around Shinra. They continue like this without words, just heated grunts that get louder and tongues that roll around each other in large circles. Izaya works his hand job a bit slower than the very eager Shinra, but Izaya’s mind grows dizzy with growing pleasure from the hot pressure around his cock. Every few pumps Izaya gives in and thrusts into his friends hand, even leaking a bit in submission to the sensation. Shinra notices, then lets him go for a second to push Izaya’s hand off of his. Now Izaya opens his eyes and glares at Shinra in confusion. 

“What are you-?” 

“You’ll like it, don’t worry.” He states as he grinds his naked cock against Izaya’s then reaches down to take hold of both in his fist, and resume rubbing. Now Izaya’s mouth hangs open as the breaths come out quick and pathetic. Shinra watches Izaya melt under him at the sensation of their skin against skin. He feels every sexy twitch and Shinra’s hand is slowly coated with their combined juices as he rubs. The sensation and building pleasure is too much for Izaya to keep quiet or hide behind the mask. 

He grinds into Shinra’s grip, then winces as the shiver runs down his spine, preparing him to shoot. 

“Close?” Shinra asks inches away from his lips. Izaya nods, and bites his lip when he can’t control the next few spastic thrusts. Shinra says nothing, in fact as Izaya cums he kisses down his friends neck and seems to rock against him as Izaya hits his peak before sinking back down. Izaya grins at the telling sensation of Shinra finishing right behind him. Hell his hand almost slips a few times from the thick combination of cum that drips down onto Izaya’s thighs. Oh but that face. Izaya locks Shinra’s eyes squeezed shut and mouth clenching in sweet agony in his memory. When Shinra finishes he all but collapses onto his friend and pants loudly into his ear. The simple heat blowing against the sensitive shell of Izaya’s ear nearly gets him hard all over again. A full five minutes pass of the two recovering slowly. Hearts slowing back to normal. Sweat drying. When Izaya decides to speak, 

“I assume this satisfies your curiosities.” He states between heavy breaths. Shinra groans, then pushes himself up. 

“For a first trial. It does.” He states with a goofy smile.


End file.
